Cumbria Groundwater Redevelopment

Case Study

United Utilities commissioned us to carry out a scoping study to identify the key issues that might constrain the development of a groundwater resource from the West Cumbria Permo-Triassic Sandstone aquifer. A report was produced which set out a provisional conceptual model of the area and identified the steps required to develop the resource in an environmentally sustainable manner.

The Challenge

United Utilities forecast a shortfall in resource availability in its West Cumbria supply zone by 2015 as a result of sustainability reductions in its abstraction from Ennerdale. In order to fill this shortfall, they commissioned ESI, now part of Stantec, to support its development of a major groundwater resource from the West Cumbria, Permo-Triassic Sandstone aquifer.

The Project

Following review of the available data ESI consulted with the relevant regulators to identify key issues. ESI prepared a report setting out a provisional conceptual model of the area and identifying the steps required to develop the resource in an environmentally sustainable manner.

A key data gap was understanding the patterns of accretion along the River Ehen (a Habitats Directive site). ESI drew up a specification for spot gauging and commissioned Hydro-logic to carry out a series of spot gauging surveys.

The surveys showed that interaction between the Permo-Triassic Sandstone and the river was a relatively minor component of flow.

Work was then carried out with UU to produce a detailed water features survey of the area to identify other potential receptors. The results were used to develop a monitoring plan providing the basis of the WR32 application.

Four new production boreholes were drilled and a testing programme for each was designed and agreed with the Environment Agency (a 5 day step test, followed immediately by 10 days constant rate and monitored recovery). Following the individual tests, a two-week group test was carried out, which showed no significant impact on flows in the River Ehen from the testing.

The Outcome

ESI supported UU through the collection of all off site data (water levels and stream flows) and through interpretation of monitoring data. All the findings were presented in a final report submitted to the Environment Agency in support of an abstraction licence.